fix: telefones em formato internacional (+351) nos links tel: e no JSON-LD

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

config/functions_site.php

@@ -126,3 +126,14 @@ function site_sitemap_urls(PDO $pdo): array {
     }
     return $urls;
 }
+
+// E.164 form for tel: links and structured data. Numbers are stored however
+// the admin typed them ("964 201 137", "+351 231 451 346"); a bare 9-digit
+// Portuguese number gets +351 so the link also works from a foreign phone.
+function site_tel(?string $phone): string {
+    $p = preg_replace('/[^\d+]/', '', (string) $phone);
+    if ($p === '') return '';
+    if ($p[0] !== '+' && strlen($p) === 9) return '+351' . $p;
+    if ($p[0] !== '+' && str_starts_with($p, '00')) return '+' . substr($p, 2);
+    return $p;
+}